The National Emergency Management Agency (NEMA) of New Zealand has issued a national advisory for tsunami activity for parts of New Zealand following the Tonga volcano eruption.
NEMA says it expects coastal areas of New Zealand on the north and east coast of the North Island and the Chatham Islands to experience "strong and unusual currents and unpredictable surges".
"We have issued a NATIONAL ADVISORY: TSUNAMI ACTIVITY following the Tongan eruption," the National Emergency Management Agency tweeted.
"We expect New Zealand coastal areas on the north and east coast of the North Island and the Chatham Islands to experience strong and unusual currents and unpredictable surges at the shore."
NEMA said that people in or near the sea should move out of the water, off beaches and shore areas and away from harbours, rivers and estuaries until at least 4am on Sunday.
"Strong currents and surges can injure and drown people," NEMA said.
"There is a danger to swimmers, surfers, people fishing, small boats and anyone in or near the water close to shore."
NEMA has said there is no need to evacuate other areas unless directly advised by local civil defence authorities.
Coastal inundation (flooding of land areas near the shore) is not expected as a result of this event.
NEMA is advising people to:
- Move out of the water, off beaches and shore areas and away from harbours, rivers and estuaries.
- Do not go to the coast to watch the unusual wave activity as there may be dangerous and unpredictable surges.
- Listen to local civil defence authorities and follow any instructions.
- Share this information with family, neighbours and friends.
NEMA said strong and unusual currents and unpredictable surges will continue for several hours and the threat must be regarded as real until this Advisory is cancelled.
The national advisory comes following a large volcanic eruption at Hunga-Tonga-Hunga-Ha'pai in Tonga.